A National Cancer database study on the demographic factors associated with mast cell leukemia.
Authors: Caitlyn Voth, Xinxin Wu, Darby Keirns, Andrew Luker, Peter T. Silberstein, Beau Hsia
Journal: Journal of Clinical Oncology (2023)

e19049 Background: Mast cell leukemia (MCL) is a rare form of malignant mastocytosis that involves a multi-system organ spread of mast cells. One study reported the 5-year overall survival rate as 16.6%. The median age of diagnosis in another study was 56 years, with a higher incidence in female patients compared to males. The rarity of MCL makes it difficult to fully understand its epidemiology, but analyzing database trends could provide valuable insight into the socioeconomic and demographic associations with MCL. Demographic data from the National Cancer Database (NCDB) was examined to assess trends in patients diagnosed with MCL. Methods: A retrospective cohort analysis utilizing the NCDB from 2004 – 2020 examined patients with a histologic diagnosis of MCL (N = 96). Descriptive statistics was used to investigate demographic factors, including: age, sex, race, Hispanic status, educational level, Charlson-Deyo score, household income, insurance type, treatment facility type, type of community, and distance from facility. The incidence trend over time was interpreted via regression analysis. Results: The NCDB had 96 patients with a confirmed diagnosis of MCL between the years 2004 – 2020. The incidence of patients diagnosed per year trended upward (R2 = 0.573). The average age of diagnosis was 60.2 years old and the median age was 63 (SD = 17.5, range = 13 – 88 years). There were more males (53.1%) than females (46.9%) diagnosed. Patients were more likely to be White (87.5%) and non-Hispanic (91.7%). 16.9% of patients were located in an area where 15.3% or more of adults do not have a high school diploma. Most individuals (71.9%) had Charlson-Deyo comorbidity scores of 0, followed by 1 (22.9%). More patients had household incomes in the highest quartile (42.9%). The most common insurance was Medicare (41.7%), followed closely by private insurance (39.6%). An academic/research facility (59.5%) was the most common place for treatment. The vast majority of patients resided in metropolitan counties (85.1%). The average distance of residence from the treatment facility was 54.2 miles (SD = 141.4, range = 0.4 – 1151.1). Conclusions: The information obtained in this NCDB analysis can be used to better understand the demographic factors associated with MCL diagnosis. The median age of diagnosis in the NCDB was 63 years with a predominance of males to females, which differs from the prior literature. Data trends show that patients were most likely White, non-Hispanic, upper quartile income earners, residing in metropolitan counties, and treated at an academic facility. Interestingly, patients were most commonly under Medicare insurance, which is reserved for those over the age of 65 or those with qualifying disabilities. Further studies are needed to understand the discrepancy between this analysis and prior literature, along with the impact this has on patterns of diagnosis, treatment, and overall survival with MCL.